Here's my opinion, and that's all it is; legionellosis is an acute condition and won't lead to retrospective claims or action. It doesn't lie dormant, symptoms occur soon after exposure, so it's not like e.g Asbestos where claims could arise well after you've moved out. You are no longer responsible for managing the premises, so any legionellosis arising there now isn't your problem; even if you had completely neglected the water system during your tenancy (which in fact you didn't) its safety is now the building's owner's (or occupier's if there is one) responsibility, so whatever you did or didn't do is irrelevant, they still have to make it safe. So I'd chuck the records, especially as the landlord now has copies. Now as I say, this is my opinion, and there could be case law that says I'm wrong, if so fair enough, John

Hello Graham, I am a School Health and Safety Officer: 'The records should be retained throughout the period they are current and for at least two years afterwards. Retain records of any monitoring inspection, test or check carried out, and the dates, for at least five years'. The copies left on the premises is fine and is good practice. However you should also retain this information especially if you were the 'Duty Holder' during the 5 year period, after 5 years you can destroy the monitoring records (if you wish to do so). I have doubled checked this information with the Local Authority Water Quality & Risk Engineer. I hope that this has fully answered your question. Kind regards Jim Cooper